Mobile stations or base stations of a radio communications system include radio receivers that receive radio frequency signals transmitted by a radio transmitter of the radio communications system. If a quadrature modulation is employed in a communications system for transmitting signals, a radio transmitter modulates the in-phase (I) and the quadrature-phase (Q) signal components by local oscillator signals that are phase offset by 90 degrees. The two modulated carrier signals are then superposed for transmission. For quadrature demodulation, the radio receiver provides two separate channels. The modulated signal is downconverted/demodulated using signals provided by a local oscillator that are again 90 degrees phase shifted to each other to produce either quadrature baseband or quadrature intermediate frequency (IF) signals. Since the original signal is processed on two separate channels for regaining the in-phase and the quadrature components, a different gain may be applied by the respective channel to the signal. In the case where the demodulation is carried out at radio frequency, most of the gain imbalance results from devices used at high frequencies that cannot match their characteristics as well as can devices used at baseband frequencies. What is needed is a way to correct the gain imbalance in an improved manner with a minimal amount of hardware.